My system info:
https://gist.github.com/OneAdder/e84b14b6e3d9ea9f5db634b58fa5be5e

Here is the log.

Have same issue
Ubuntu 18.04
Steam version: Feb 18 2019

My download speed is 100 bytes but when CS GO download its modifications it was normal(700 kb/s)
I try to reinstall steam and system, nothing changed.
Here is log.
https://gist.github.com/tonysh3/a5b5b10452f8467cc618204c688230b6

I don`t know what happened, download was 100 bytes/s for 1-2 minute and now speed increased to normal 800kb/s.
Here is log which includes yesterday and today launches, if you need this.
https://gist.github.com/tonysh3/180bd6903b70c3f21ae4489bc8ad2e5c

Is there any progress or some idea about what might be causing it? I tried purging Steam and reinstalling it from scratch, the result is still the same. I cannot find any workaround to solve the issue.

I still have this issue. Download start with 1 second 500kb speed, than it became 3-4 kb/s, it increases from time to time a bit at the end of 10 mb donwload it became 50kb/s. Still have this peaks at download.

I don`t understand. Start downloading game 1 minute after taking screenshots above.
Speed is normal without any peaks

try disabling ipv6 on your system

Wow, that helped. @ThomasStegbuchner Thank you very much!
@kisak-valve Could you fix this issue with IPv6? I have to disable it systemwide to download something. It's not a perfect workaround.

ipv6 disabled didn`t work out for me
same speed like before

I am (was?) seeing the same thing. Once I disabled ipv6 (sudo sh -c 'echo 1 > /proc/sys/net/ipv6/conf/eth0/disable_ipv6') downloads immediately started up again.

@bcrochet Interesting whether this issue appears randomly under both Debian and Ubuntu or under Debian only. If the second, I think it could be solved by investigating the difference in how ipv6 works under both systems

Hi, I also suffer from this issue. The only workaround is to disable IPv6 - but this is very suboptimal.
I've also opened a discussion on the forums here: https://steamcommunity.com/app/221410/discussions/0/3247565033758861331/

I'm running on Ubuntu 18.04 with HWE.

the same issue on Fedora 29

In general my IPv6 works fine, perhaps is the API Valve are using that may be not performant?
Perhaps they're using async-io on Linux (instead of epoll)?

Hi, I also got this issues, but disabling IPv6 doesn't relay solve the problem. The download speed toggles between 0 kb/s and 6 mb/s. log

Having this issue as well. Manjaro Linux, Steam version Feb 18, 2019, API v018, Package Version 1550534751.

No IPv6 on network and disabled in OS. Speed tests consistent at 45-80 Mbps.

That's a pretty significant difference. Any telemetry we can pick up in Steam to help diagnose?

I can confirm that disabling IPv6 on my Fedora 29 machine "fixed" the problem.

You can as a test try

ip6tables -I INPUT -m state --state NEW -j LOG --log-prefix "valvetest:"
ip6tables -I INPUT -j REJECT
ip6tables -I FORWARD -j REJECT
ip6tables -I OUTPUT -m state --state NEW -j LOG --log-prefix "valvetest:"
ip6tables -I OUTPUT -j REJECT

If you see hosts getting logged it's posible somethings retrying ipv6 because it's not either honoring a reset or, more likely, waiting for ipv6 to timeout.

Assuming you're not using v6,

ip -6 route get 2002::

Should return network is unreachable or some such.

Can confirm this problem with openSUSE Tumbleweed.
Disabling IPv6 did not help.

I have the same issue in Ubuntu 19.04 and disabling ipv6 did nothing. However, changing my download region to Netherlands instead of Germany made my download speeds go from ~50KB/s to 5 MB/s (which I would expect from my connection).

content_log.txt

Linux Mint 19.1 Cinnamon, 4.15.0-50-generic.
Disabling IPv6 did help immensely. 20 KB/s to 46.4 MB/s.

After steam update speed is better but it is not as high and constant as if we disable ipv6
These commands work for me
sysctl -w net.ipv6.conf.all.disable_ipv6=1 sysctl -w net.ipv6.conf.default.disable_ipv6=1

After steam update speed is better but it is not as high and constant as if we disable ipv6
These commands work for me
sysctl -w net.ipv6.conf.all.disable_ipv6=1 sysctl -w net.ipv6.conf.default.disable_ipv6=1

Same here - the update made it better, but with IPv4 I get to use my 1 Gbps at full speed...

Ammending previous post: adjusting IPv6 settings no longer works. Back to slow speeds.

@bcrochet Interesting whether this issue appears randomly under both Debian and Ubuntu or under Debian only. If the second, I think it could be solved by investigating the difference in how ipv6 works under both systems

I'm on Fedora. And I've seen it across Fedora 29/30, and Fedora 30 Silverblue.

Hello there,

This might not be a match with the issues that everyone is experiencing here, but I had the "slow download speed by short bursts" using ubuntu 18.04

It turned out the steam library I was using was on an ntfs drive (dual boot system so some of my drives are ntfs, the only with room left in it was) mount. As per the first answer right here https://gaming.stackexchange.com/questions/253695/abnormally-slow-speeds-downloading-from-steam I changed the fstab config of this mount to async (was sync). After unmounting and remounting, the problem was fixed (comparable download/update speeds as windows).

For the record, I do have dnsmasq installed (since i'm using it for other purposes). I didn't touch any IPV6 conf.

I hope it helps anyone (although I doubt it's the cause of most people posting here issues).

It seems the same issue resurfaced again. After disabling IPv6 download speeds seems to have picked up. Ubuntu 18.04 LTS with HWE 4.18.0-25-generic.

I have same problem with download speed. If i disable IPv6 i can reach maximum downloading speed.

OS: Ubuntu 18.04
kernel: 4.15.0-54-generic
Steam Runtime Version:  jenkins-steam-runtime-beta-release_0.20190320.2

Had to resort disabling IPv6 to get full download speeds (1 Gbps)... Weird, I thought it was fixed some weeks back?
Ubuntu 18.04 with HWE.

As of today this problem still exists. I'm on 4.16.18-galliumos.
Turning off ipv6 did correct the problem.
I followed this guide to do it: https://easyengine.io/tutorials/linux/disable-ipv6/

Good luck!

@ehudnoleft solution fixed it for me on Ubuntu 18.04

Unfortunately the issue still persist. Valve should give us the option to turn off IPV6 at app level instead of having to manually disable at OS level...

Thanks - is there any update on this?

@kisak-valve any way to disable IPv6 from Steam client as a workaround instead of disabling it system-wide?
Any way to set socket creation as IPv4 stream instead of IPv6 (i.e. force specify AF_INET instead of AF_INET6 in the domain parameter) when steam creates a connection?

Thanks - is there any update on this?

@kisak-valve any way to disable IPv6 from Steam client as a workaround instead of disabling it system-wide?
Any way to set socket creation as IPv4 stream instead of IPv6 (i.e. force specify AF_INET instead of AF_INET6 in the domain parameter) when steam creates a connection?

This seems to be fixed in the beta client at least. I would give that a shot.

This seems to be fixed in the beta client at least. I would give that a shot.

Not really? Download speed of patches was around 300 KiB/s...?
My Steam version is 7th Nov build...

Disabling IPv6 with the following commands worked for me on Ubuntu 18.04 LTS

sudo sysctl -w net.ipv6.conf.default.disable_ipv6=1
sudo sysctl -w net.ipv6.conf.all.disable_ipv6=1
sudo sysctl -w net.ipv6.conf.lo.disable_ipv6=1
sudo systemctl restart networking

I was getting abysmal speeds of 100 Kbps before, after that it spiked up to 7 Mbps.

If only there was an easy way to LD_PRELOAD the steam client, I could pre load a library with a modified socket API to fake the system doesn't support IPv6...

Just wanted to say that this issue it's still alive and well.

Disabling Ipv6 returns downloads to the expected speed. The issue is that I need to have Ipv6 enabled, so this workaround is not very useful for my situation.

Hi Valve (@kisak-valve), this has been open for almost a year.

Having the workaround to always disable IPv4 when downloading a big game/update is ok for some months - but now, after such long time, could you at least provide the option to switch off IPv6 (only use IPv4) usage for the Steam client?

Thanks!

Hi, any update about this ask?
Would it be possible to implement it?

Update: looks like things are now working ok (I'm on latest beta) and can use 100% my bandwidth without disabling IPv6.

@kisak-valve should we close this?

ipv6 seems to works if you are on latest beta

Unfortunately I'm still experiencing this behavior. I tested OpenSUSE TW and Leap, Manjaro and Ubuntu 20.04 all of these four distributions had this problem although all systems were up to date and the steam beta was enabled.

When IPv6 is enabled I only reach download speeds around 15-600 Kb/s even though I got a 100 Mb connection.

I'm also experiencing this behavior. I'm not sure since when exactly it's happening again, but i'm sure it was not there 2/3 months ago. Disabling IPv6 solves the Problem.

Working ok on Ubuntu 20.04.1 - Steam beta.

Experiencing this on archlinux in steam and steam beta. Disabling ipv6 fixes download issues.

Experiencing this on arch and ipv6 disabling not working for me.

Experiencing this on Kubuntu 20.04 (Ubuntu 20.04.3 LTS x86_64). Kernel: 5.11.0-41-generic . Disabling IPv6 fixes this problem.

Also seeing this on Kubuntu 20.04. Disabled IPv6 and all is good now, download speeds are normal again.

Linux 5.13.0-22-generic #22~20.04.1-Ubuntu SMP Tue Nov 9 15:07:24 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux

I'm on Ubuntu 20.04. Got a peak of 133Kb/s. Disabled IPv6, but still slow.

If anyone stumbles upon here currently experiencing slow download issues: https://github.com/ValveSoftware/steam-for-linux/issues/10248